Current ALSA SoC Sound Card basically consists of CPU/Codec/Platform components. If system uses Kernel modules, we can disable these drivers by using rmmod command. In such case, we can't disable CPU/Codec/Platform driver without disabling Sound Card driver.
But on the other hand, we can disable these drivers by using unbind command. In such case, we can disable these drivers randomly. In this case, we can create dirty Sound Card which is missing necessary components.
(1) If user disabled Sound Card first, but did nothing to other drivers, user can't use Sound because Sound Card is no longer exists. (2) If user disabled CPU/Codec/Platform driver randomly, but did nothing to Sound Card, user still be able to use Sound Card, because dirty Sound Card still exists. In this case, Sound system will be crashed if user started sound playback/capture. But we can't block such random unbind now.
To avoid Sound Card crash in (2) case, we need to unregister Sound Card whenever CPU/Codec/Platform component were unregistered. This patch solves this issue.
Signed-off-by: Kuninori Morimoto kuninori.morimoto.gx@renesas.com --- sound/soc/soc-core.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c index 07e4eec..52760bd 100644 --- a/sound/soc/soc-core.c +++ b/sound/soc/soc-core.c @@ -3236,6 +3236,11 @@ static void snd_soc_component_cleanup(struct snd_soc_component *component)
static void snd_soc_component_del_unlocked(struct snd_soc_component *component) { + struct snd_soc_card *card = component->card; + + if (card) + snd_soc_unregister_card(card); + list_del(&component->list); }